I wouldn't be too worried. I saw them in Omaha and they put on an incredible show, full of energy. It's cold and flu season and Jon has had something (I've read strep throat, the flu, and/or an upper respitory infection) so he had a few off nights with a scratchy voice, but most people have reported that he sounded great at most of the shows. Richie is obviously going through a bad time right now and several people have voiced concerns about his off nights, but he's a professional and he'll probably be even more on fire than usual for pouring his heart and soul into the music. Bon Jovi overwhelmingly puts on great shows and even their worst shows are better than many acts best shows.